A New Siloxane Functional Polymer for Chemical Vapor Sensor

A new hydrogen-bond acidic groups functionalized siloxane polymer for quartz crystal microbalance sensors (QCMs) application was synthesized via O-alkylation, claisen rearrange, hydrosilylation and hexafluoroacetone groups (HFA) electrophilic addition reaction. This hexafluoroisopropanol functionalized polysiloxane was confirmed by FT-IR and ¹HNMR, and coated onto a AT-cut 8 MHz QCM sensors to investigate its gas sensitive responses to the organophosphorus nerve agent stimulant dimethyl methylphosphonate (DMMP) vapor as well as other organic chemical vapors. The results indicated that frequency change of this functionalized polysiloxane based QCM sensors to the DMMP vapor were completely linear, and with a regression coefficient of 0.9993 in the concentration range of 10-60 ppm. In addition, the sensitivity of the fabricated QCM sensors to DMMP was up to 23.07 Hz/ppm, and much higher than the other chemical vapors, the detection limits of this fabricated QCM sensors was as low as 0.13 ppm.